The deal, which is yet subject to competition checks, marks Emirates subsidiary dnata’s first foray into the German market.
Tropo, which was itself acquired by German media group ProSiebenSat.1 in 2012, is a low-cost, last-minute holiday and hotel provider.
It has flourished in recent years despite staunch competition thanks to significant backing from TV advertising.
The business also provides travel services to other operators, including Eurowings Holidays - the tour operation arm of German low-cost airline, Eurowings.
Iain Andrew, dnata divisional senior vice-president, travel services, said: “This acquisition enables us to enter the important and valuable German travel market, and enhances our portfolio of travel services in Europe.
“We see potential for significant synergies between Tropo and our other travel businesses around the world to provide very attractive and unique offerings to inbound and outbound travellers to and from Germany.”